Conformation Analysis and Absorption Properties of Anthraquinone Dyes—A Quantum-chemical Approach

Abstract

For a series of anthraquinone dyes the excited state properties are discussed as a function of the molecular conformation by using semiempirical INDO-MO calculations. It is demonstrated that the absorption maxima depend on details of the geometry as, e.g. inner hydrogen bridges and different substituents at the aromatic framework. In most of the cases the transition moment of the VIS absorption band has a strong component parallel to the long molecular axis, a result, which is important for practical use in display technology. The polarization of the electronic transition is strongly dependent on the position of the substituents at the anthraquinone core and the nature of these groups itself, too.